[subwayrocket]

Been getting this arc stuttering thing the last 2 times I welded . When it does it, the pitch of the frequency seems to go down and the size of the puddle immediately gets smaller by about half...sometimes the arc will drop.
(see video below , 10 sec mark) I tried a few different pieces of 6061 that I welded on no prob before , also tried 0.045" and 0.092" alum at 55 and 110 amps . Tried a few different freshly ground tungstens (2% lant) , checked dinse, ground and clamp connections ...even tried clamped right to the material . Tried frequencies from lowest up to 250hz , no difference ...tried anywhere from 30 to 45% EP balance . no difference . I've had this happen ocassionally , and more often on cast alum , but it was doing it a lot yesterday... yeah I kno...I dipped the tungsten at the end...I was tired, haha

Anyone know what's going on here ? Thanks in advance guys !

I stopped and took some crude video , im just laying beads here, and/or bead on plate on clean 0.092" Alum 6061,
4043 rod, machine set a little over 100 amps, pedaling . The phone cam is close to the water cooler,
some of what you hear is the pump .

https://youtu.be/JK0LX7zQQDg

[noddybrian]

I'm sure better qualified guys will chime in but I did'nt hear that much change in frequency on the video - it would help to see the welding - maybe put fixed shade in front of camera ? if you have ruled out most of the obvious causes of power fluctuations externally the cause maybe internal to the machine or more likely a pot going bad in the pedal or even a pedal cable / plug fault giving resistance change if it is actually only welding current that is changing - I would disconnect the pedal - set amps on the front panel & try the same weld again - I realise you can't taper off except using slope down - but it would eliminate external influences - hope this helps & you get it sorted - what is the machine ? maybe worth a Google on common faults of that model ?

[subwayrocket]

[quote="noddybrian"]I'm sure better qualified guys will chime in but I did'nt hear that much change in frequency on the video - it would help to see the welding -quote] You don't hear it bogging out ? The sound of the arc is definitely changing, and the puddle shrinks when it does it. It starts doing at around 10 seconds into the video , and I am not dipping the tungsten or touching rod to it when it does this. It did it when just running bead on plate, no filler . I had this machine a few months , it's a 250EX . I will keep troubleshooting , figured id see if anyone else knew what this was . Also, it's a gas lens, 7 cup and 18cfh . Pretty much everything i'm doing is the same as I have been doing , just that now i'm getting this stuttering .

[big gear head]

I had a MIG welder do something like that years ago. I found a loose cable inside the machine.

[noddybrian]

My hearing is not great - it's another thing I did'nt look after from a young age ! - I can hear a difference - but would'nt say it's frequency - just amps dropping - so the question is why - hence run with no pedal - fix current on front panel - if it still does it & you have been through the leads I would start to suspect it's internal - but on the chance of a bad torch crimp on the power lead I would try a different torch - if not I'd try the green forum or contact them direct as it's still pretty new & I hear they're customer service is good.

[subwayrocket]

I can hear a difference - but would'nt say it's frequency - just amps dropping - so the question is why -- if it still does it & you have been through the leads I would start to suspect it's internal - but on the chance of a bad torch crimp on the power lead I would try a different torch -.

yep , just tried that . Hooked up my 17 and ran a perfectly stable arc across the same piece I experienced the problem from yesterday. Took the whole torch apart again, and this time the fittings too.
I opened up the Dinse connector, took all that apart, the power lead compression flange (looks like a brass mushroom) had some crud on it, and was damp. Just cleaned that out with some scotch brite, while the water ran out...make sure I don't get any particles up I there. Haven't tried it yet. Hopefully this fixes it...else I be back on the 17 for a while.
Thanks guys for chiming in , appreciated !
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CK20-Water-Power.jpg (45 KiB) Viewed 2049 times

[noddybrian]

Glad you seem to have sorted the problem & it was a cheap fix - sometimes it's the least likely little things that gets us scratching the head ! water cooled torches while great can add complications so always worth trying a standby torch if available to rule it out.

[Otto Nobedder]

Subwayrocket, what are you using for coolant in that torch?

I had a major issue on a contract job, smoking torches, until I discovered the rental company our machines came from had cheap automotive antifreeze and very hard tap-water in them.

In a warm climate where freezing is not an issue, use distilled or de-ionized water. In freezing climates, use "low conductivity" antifreeze/coolant available from your LWS, or a mix of the two.

Steve S

[subwayrocket]

Subwayrocket, what are you using for coolant in that torch?
Steve S

I've got 5 gallons of distilled water and 3 gallons of RV antifreeze .
Hope to get it fired back up again tonight or tomorrow . At least I know it's not the machine .

[Otto Nobedder]

Subwayrocket, what are you using for coolant in that torch?
Steve S

I've got 5 gallons of distilled water and 3 gallons of RV antifreeze .
Hope to get it fired back up again tonight or tomorrow . At least I know it's not the machine .

RV antifreeze is a good option. It has no need to have "corrosion preventatives" and other nonsense chemicals that HF disagrees with.

Steve S

[big gear head]

I used the Miller coolant in my Syncrowave 250.

[subwayrocket]

It worked good most of the day , but then after running a few feet of beads doing Jody's "Aluminum Drill" it started doing
that sputtering again, I noticed it whenever I ramped down about halfway on the pedal. It didn't do it as consistently as the last time, but I suspect it will only get worse again. Gonna have to take the Dinse apart again and inspect
the water/power connection again .
----------------------------------
update
I opened up the Dinse and took apart the power/water fitting , and it's all clean in there ...I thought I had this figured out...now i'm not sure. ...idk
i'll try things again next day off ...see what happens. Thanks for the replies guys !

[subwayrocket]

bump....
It's still happening . I didn't get any response from anyone who know's what this is.
Anyone know what's going on here please chime in. Here's the vid again, the stuttering you see is
not me dipping the tungsten or touching the filler to it. Also seems to do it if I pulse down on the pedal.
(The phone cam is close to the water cooler,
some of what you hear is the pump)

https:/jr/youtu.be/JK0LX7zQQDg
-----------------------------------
first one third of the tube went ok, then the unstable arc stuttering started and I got crater eyes as I was pumping the pedal...it would stutter on the down slope of the pedal pump---the second pic

NoCraterEyes.jpg (45.22 KiB) Viewed 1908 times

CraterEyes.jpg (37.69 KiB) Viewed 1908 times

[Otto Nobedder]

Man, that's screwy sounding.

I can't make any guess that falls under "user-serviceable parts".

I think that's a question for the manufacturer.

Steve S

[subwayrocket]

Man, that's screwy sounding.

I think that's a question for the manufacturer.

Steve S

I'll have to try that

[Poland308]

Ohm them both out. With a good meter. And check them both with and without the leads attached. Then try wiggling the torch while you test it. Could be a hairline crack or a bad connection.

[subwayrocket]

Good suggestions, thanks much. I'll hook them up to my fluke meter tomorrow. Try the wiggling while testing too. Thanks much !

[subwayrocket]

Ohm them both out. With a good meter. And check them both with and without the leads attached. Then try wiggling the torch while you test it. Could be a hairline crack or a bad connection.

Ohm tested both torches with my Fluke 12 , the CK17 (12 ft lead) measures 0.2-0.5 ohms and wiggling the cable caused a small bounce between 0.2 and 0.5 ohms . For the CK20 (25 ft cable) it measures between between 0.3 and 0.7 ohms, wiggling the cables around caused only a small fluctuation in both torches. With the cables stabilized from the torch heads, wiggling and tapping on either heads caused no fluctuation. Both torches are disconnected from the welder. I will have to take apart the whole 20 torch head now and check the connections . If I don't find anything, i'll have to live test the 20 and 17 back to back again . In the cooler I've got 6 gallons distilled water and 3 gallons RV antifreeze .

Anyone else ever had this happen, please comment. Thanks
-----------------------------
CK20 resistance, tungsten to dinse

Test20Torch.jpg (59.81 KiB) Viewed 1886 times

CK17 resistance, tungsten to dinse

Test17Torch.jpg (66.54 KiB) Viewed 1886 times

Cooler

Cooler.jpg (54.61 KiB) Viewed 1886 times

RV Coolant ingredients

RV Antifreeze ingredients.jpg (82.95 KiB) Viewed 1886 times

[Poland308]

It could be a hairline crack in the insulation that only opens up when the torch gets hot. You did say the first part of the weld went ok.

[subwayrocket]

Yeah I was thinking that but I didn't want to pose a "leading" question.
I've got the torch head apart, of the 3 lines, only one I can put a 6 or 7mm wrench on , the other two seem to only have knurled hand twist fittings ...hate to put pliers on it and ruin something...Which one is the power in ?
Thanks guys for helping out. I appreciate it.

[Poland308]

There not color coded?

[subwayrocket]

There not color coded?

I opened up this one, this fitting looks clean . I didn't unscrew the other two twist on connections.
I don't see any color code, three black tubings .
...and again, thanks for commenting/posting suggestions. Appreciated !

20150927_183727.jpg (39.26 KiB) Viewed 1831 times

[Poland308]

Try your torch without running the coolant through it. Maybe the short is going through the coolant.

[subwayrocket]

Try your torch without running the coolant through it. Maybe the short is going through the coolant.

I wondered about that, since the coolant circuit is in direct contact with the "live" torch head .
(My stainless reservoir tank is up off the cement, on wood 2x4's)
I'd have to disconnect it and blow out the line, yes ?
What amperage and how long could I run it with it disconnected from the cooler ?
I'm guessing low amps and just long enough to see ???
Don't wana burn up the power cable ...haha

Thanks much !

[AndersK]

Try your torch without running the coolant through it.

Dont!

My own experience, 5 sec welding without coolant was enough to melt water return...